Transilluminating flashlight



Sept. 8 1970 I J. J. THOMAS 3,527,932

TRANSILLUMINATING FLASHLIGHT Filed Nov. 16, 1967 INVENTOR. JAMES J. THOMAS ATTORNEY United States Patent once 3,527,932 TRANSILLUMINATING FLASHLIGHT James J. Thomas, Morganton, N.C., assignor of fifty percent to Billie E. Newton, Morganton, N.C. Filed Nov. 16, 1967, Ser. No. 683,600 Int. Cl. F21v 33/00 US. Cl. 240-64 4 Claims ABSTRACT OF THE DISCLOSURE BACKGROUND OF THE INVENTION One of the medical tests frequently indicated in the examination of a newborn baby is a test to determine whether the infants brain has formed correctly, or whether his skull is merely filled with fluid. One method of performing this test is by placing a light directly against theinfants skull in a completely darkened room, whereupon the light rays penetrate the skull and if the head is filled with fluid, the light rays will be transmitted to and illuminate other parts of the head. However, if the babys brain has developed properly, there will be no resulting transilluminating effect.

In order to perform this test properly, the room must be completely dark, the light must be adequately shielded and directed into a prescribed area of the babys head, and none of i the light may be allowed to escape laterally of said prescribed area.

SUMMARY OF THE INVENTION The present invention comprises a conventional flashlight and a novel, generally cylindrical hood or shield mounted on the front thereof. The hood is formed of a flexible material such as plastic and is opaque to prevent the passage of light rays therethrough. In use, the open free end of the hood is pressed against the head of the infant and the soft flexible nature of the material allows the terminal or free end portion of the hood to collapse upon itself and effectively form a tight light seal between the hood and the prescribed portion of the head. This prevents lateral transmission of light rays, and directs all of the light onto the surface of the head within the periphery of the terminal end of the hood.

It is therefore an object of this invention to provide a source of illumination for use in transilluminating tests, which directs all of the emitted light rays toward a prescribed area and prevents lateral escape of the light rays from said area.

It is a further and more specific object of the invention to provide a transilluminating flashlight which includes a hood or shield mounted to the forward end thereof, said hood, in use, forming a tight light seal to prevent lateral emission of the light rays.

It will be apparent that the subject matter of the invention is susceptible of other uses and constructions than the illustrated embodiments, and other objects and a fuller understanding of the invention may be had by referring to the claims and the accompanying drawings in which- FIG. 1 is an environmental perspective view showing the apparatus of the present invention as used in a transilluminating test against the head of an infant;

FIG. 2 is a side'elevation, partly in section, of the hood 3,527,932 Patented Sept. 8, 1970 of the present invention mounted on a standard flashlight;

FIG. 3 is a side elevation, partly in section, and with parts broken away, showing an alternate embodiment of the hood assembled on a conventional flashlight;

FIG. 4 is a side elevation, partly in section, of another embodiment of the hood mounted on a flashlight having a tapered front portion; and

FIG. 5 is a side elevation, partly in section, and with parts broken away, showing still another embodiment of the hood assembled on a conventional flashlight.

Referring now more particularly to the drawings, FIGS. 1 and 2 show a transilluminating device 10 according to one embodiment of the invention and comprising a conventional flashlight 12 in a doctors hand H being urged against an infants head C.

The flashlight 12 includes the usual barrel 14 having external threads 16 at the forward end thereof, which normally receive a lens-retaining cap 17, a bulb 18, a lens 20, and a reflector element 22. The flashlight described above is merely a standard, commercially available prodnot and does not, per se, form a part of the invention.

Rather, the invention resides in the structure of a hood 24, which is suitably attached to the forward end of flashlight 12 and comprises retaining ring portion 26 and flexible shield portion 32, which are preferably formed as a single unitary structure.

Retaining ring portion 26 may replace the usual lensretaining cap 17, or may, as shown in FIGS. 1 and '2 be drawn over the cap 17 and frictionally retained. The retaining ring 26 may be deformable to define internal threads 28 which are complementary to external threads 16 on the barrel of flashlight 12 and on cap 17 to assist in attaching hood 24 to the flashlight. An annular groove 30 may be formed internally of the retaining ring portion 26 about the periphery of the lens 20 as a further aid in attaching hood 24 to the flashlight 12, or, to hold the lens in place if lens-retaining cap 17 is omitted.

Flexible shield portion 32 extends forwardly from groove 30 and terminates at 36 in a circular opening providing communication between the source of light rays and the head of the infant.

Although shield portion 32 is generally cylindrical, it has a convex mid-portion of enlarged diameter between the groove 30 and terminal end 36 to allow the shield portion 32 to bend or flex outwardly when pressure is applied and thus aid in obtaining an effective seal agalnst the infants head with a minimum of pressure required against the soft head of a newborn baby.

The hood 24 may be formed of any suitably flexible plastic material, such as polyurethane, and of suflicient thickness for adequate attachment and light fastness. Preferably, the hood 24 is ultra black to minimize the transmission of light rays through its walls.

In the alternate embodiment shown in FIG. 3, shield portion 32 may be modified by securing a ring or gasket 36 of sponge-like material to the forward end 36 thereof, thus providing between the hood 24 and the infants head additional protection for the infants head against undesirable pressure.

FIG. 4 shows an alternate form of flashlight 12', wherein the forward end of said flashlight including said lensretaining cap 17 is tapered slightly inwardly, so that the front end of flashlight 12' is of a diameter slightly smaller than the barrel portion of said flashlight. Hood 24' when used on flashlight 12' includes a slightly enthiokened retaining ring 26 in order to insure an adequate attachment and light fastness.

Shield portion 32 as shown in FIG. 5 comprises accordion-like pleats 40 extending circumferentially around the enlarged mid-portion of shield 32, and substantially improves the flexibility thereof.

In use, the infant is placed in a completely dark room for a period of time in order for the examining physicians eyes to become accustomed to the darkness. The transilluminating flashlight 10 is then positioned with end 36 or 36 of flexible hood 32 positioned against the head or other portion of the infant to be examined.

The free end of the hood 32 is pressed against the infant sufliciently to flex the enlarged mid-portion of the hood and in doing so to form an effective seal against lateral transmission of light rays between the infant and the flashlight. Toward this end, it is an important feature of the invention that the hood 24 be of such flexural rigidity that it will assimilate applied pressure as by collapsing on itself or by flexing adjacent its mid-portion, as described, responsive to the application of pressure so light as not to endanger the infant. At the same time, the flexural rigidity of the hood is such that it will permit transmission of suflicient pressure to the infant to form an effective seal.

The light is then switched on, and the testing commenced. If the babys brain has developed normally, the tissue within the head will obstruct the light rays, and there will be no transilluminating throughout the rest of the head. However, if the brain has not developed normally and the brain substance is replaced by water, the light rays will penetrate the skull and be visible through other portions of the head, as is well known in the medical arts. It is also possible to use the transilluininating flashlight in testing other fluid containing portions of the body such as the abdominal cavity. Also, if desired, a red light may be placed on the rear end of the flashlight, which will not affect the test, however will given some illumination in the dark room without losing the dark adaptation.

It is within the spirit and scope of this invention to vary the dimensions of the hood for use in different transilluminating tests, depending on the area to be tested.

In the drawings and specification there have been set forth preferred embodiments of the invention, and although specific terms are employed, they are used in a 4 generic and descriptive sense only and not for purposes of limitation, the scope of the invention being defined in the claims.

I claim:

1. A transilluminating device comprising, in combination:

(a) a flashlight having a source of light at one end thereof;

(b) a tubular open ended hood for attachment to said one end of said flashlight;

(i) said hood projecting beyond the flashlight and at least the projecting portion of said hood being formed of a light impervious material which is convex and of accordion-pleated configuration along its longitudinal axis so as to be deformable longitudinally in response to the application of axial pressure against the free end of said hood; and

(0) means for attaching said hood to the flashlight.

2. A transilluminating device according to claim 1 wherein the hood is accordion-pleated throughout its longitudinal extent and frictionally retained in overlying relation on the flashlight.

3. A transilluminating device according to claim 2 wherein the end portion of the hood which is frictionally retained on the flashlight is formed of resilient material and conformable to the surface irregularities of the underlying portion of the flashlight.

4. A transilluminating device according to claim 3 wherein the inside diameter of at least that portion of the hood overlying the flashlight is less than the outside diameter of the underlying portion of the flashlight.

References Cited UNITED STATES PATENTS 881,017 3/1908 Morse. 2,215,829 9/1940 Evans. 2,334,899 11/1943 Bosten et al. 2,910,576 10/1959 Meese 24041.6 2,972,346 2/1961 Eddin-gs.

NORTON ANSHER, Primary Examiner D. J. CLEMENT, Assistant Examiner US. Cl. X.R. 

